Rename registration SetTransform to SetInitialTransform

This renaming is more consistent with the ITK interface, the examples
and tests have been updated.

Additionally, the and "InPlace" flags has been added to the set method.

Change-Id: I7143d6801bde1ad2e7d6caf6ed88e4e5d7ed70dc
Adding testing for registration transform inplace option

Also accessor method to get the current state of the in-place option.

Change-Id: I549f7bd3ba8ea7abf120c685e6f08e0b9e455885
Adding documentation for SetInitialTransform method

Change-Id: Id905ba92d318d9531484513936cde009d48cf125
Adding new registration methods to set moving and fixed transforms

Change-Id: Iff2f5366c40a3c841ea8c381d4073a7864be1997
Adding testing for the initial transforms

Change-Id: I5abcef163dde2e4783002d576c46a8eab474f30c
Adding doxygen documentation for initialize transform methods.

Change-Id: I64e6d946127414971fe644ede1003080223007ff
Merge topic 'SIMPLEITK-574_AddTransformInitialMethodsToRegistration'

f58c48fe Adding doxygen documentation for initialize transform methods.
95f04d99 Adding testing for the initial transforms
939cef2d Adding new registration methods to set moving and fixed transforms
fa1243c5 Adding documentation for SetInitialTransform method
c059562c Adding testing for registration transform inplace option
26d8ecb4 Rename registration SetTransform to SetInitialTransform